Multimodal Therapy of Squamous Cell Carcinoma of the Anus With Distant Metastasis: A Single-Institution Experience

Background Because of the rarity of the condition, studies concerning the management of patients with squamous cell carcinoma of the anus with distant metastasis are scarce. The available studies indicate poor outcomes with exclusive chemotherapy. Objective Our aim was to evaluate the impact of multidisciplinary treatment on overall survival among patients presenting with metastatic squamous cell carcinoma of the anus. Design This was a retrospective study. Settings The study was conducted at a single French institution between 2000 and 2014. Patients Consecutive patients with histologically proven, newly diagnosed, or recurrent metastatic squamous cell carcinoma of the anus were included. Interventions Study interventions included multimodal therapy combining systemic chemotherapy and local ablative treatment to remove all metastases through surgery, radiofrequency ablation, or radiotherapy. Main outcome measures The primary outcome measure was overall survival. Results Fifty patients (median age, 62 years; men/women: 8/42) fulfilled the inclusion criteria, and 39 were available for Response Evaluation Criteria in Solid Tumors. Forty had metastatic relapse after previous treatment of localized disease, and 10 presented with synchronous metastasis. P16 status was not available. Patients received at least 1 chemotherapy regimen, including 5-fluorouracil-mitomycin C (n = 22), cisplatin-5-fluorouracil (n = 20), or 5-fluorouracil alone (n = 3). Thirteen also had surgical metastasectomy, 11 had radiotherapy, and 6 had radiofrequency ablation. Median overall survival was 20.0 months (95% CI, 18.2-21.8 mo), and median time to failure of strategy was 6.0 months (95% CI, 2.9-9.1 mo). Overall response rate was 56% (95% CI, 40%-73%). Outcomes from the 5-fluorouracil-mitomycin C and cisplatin regimens did not statistically differ. Patients treated with multimodal therapy had a median overall survival of 22.0 months (95% CI, 15.3-28.6 mo) versus 13.0 months (95% CI, 9.5-16.5 mo; p = 0.002). Median time to failure of strategy was 10.0 months (95% CI, 4.2-15.7 mo) versus 5.0 months (95% CI, 2.8-7.2; p = 0.007). After 2 years, 40% of patients with multimodal treatment and 20% of those without ablative treatment were alive. Limitations This study is limited by its retrospective design and modest sample size. Conclusions Stage IV squamous cell carcinoma of the anus outcomes are poor, but first-line chemotherapy can enable good response rates. Other treatment modalities, including surgery, radiotherapy, and thermoablation, should be considered, because they may provide a survival advantage. See Video Abstract at http://links.lww.com/DCR/A336.